Early Indicator for Alzheimer’s Disease Found

Research Can Help in Early Detection, Treatment

This confocal microscope image of a giant neuron in the brain of a lamprey shows the neuron expressing and secreting human tau protein (the reddish tendrils). Biology Prof. Garth Hall says that tau secretion occurs not only in a biological model system like this lamprey in the lab, but also in the cerebrospinal fluid (CSF) of Alzheimer’s disease patients — that is, the neurons don’t have to die first to release tau to the CSF, as has long been believed.

02/03/2012

By Edwin L. Aguirre

A team of researchers from UMass Lowell, MassBay Community College, Veterans Administration Medical Center and Boston University has discovered an early indicator for Alzheimer’s disease (AD).

Assoc. Prof. Garth Hall of UMass Lowell’s Biological Sciences Department and his former Ph.D. students Sudan Saman and WonHee Kim, together with their co-investigators, found that high levels of a biomarker for the tau protein — called phosphotau or AT270-tau — in exosomes can indicate early stages of Alzheimer’s disease. Exosomes are tiny bubble-like membranous structures released from cells that can be found in the cerebrospinal fluid (CSF) of patients.

“The idea is that tau secretion probably occurs before the neurons, or brain cells, die in AD patients, and, if so, the levels of secreted tau in the CSF — and possibly blood — might be able to predict whether a person would get AD before he or she actually starts to show symptoms,” explains Hall.

“Most importantly, it would permit the identification of AD patients while they are cognitively intact — that is, before they lose a lot of neurons — so they can be enrolled in clinical trials for drugs that might cure Alzheimer’s disease,” he says. “This has been one of the biggest obstacles to finding a cure for AD; our study marks a big step forward in removing that obstacle.”

The results of their research were recently published in the Journal of Biological Chemistry. Saman is currently an adjunct faculty member at MassBay; Kim is a postdoctoral fellow at Tufts.

A Leading Cause of Death Among Seniors

Alzheimer’s is the most common form of dementia. It’s a degenerative and terminal brain disorder that typically afflicts people older than 60 years, seriously diminishing their memory, thinking and ability to carry out daily activities. So far, there is no known cure for Alzheimer’s.

According to the Alzheimer’s Association, as many as 5.4 million people in the United States are living with the disease. It is now the fifth leading cause of death among seniors. The association estimates that in 2011 the direct and indirect costs of Alzheimer’s and other dementias to Medicare, Medicaid and businesses amounted to about $183 billion. It also places a great burden on their families.

Garth and his team have filed a patent application on the secreted tau biomarker and are looking to partner with a large biopharmaceutical firm to develop a commercial diagnostic for AD based on their research.

“I am currently involved in a commercial venture with Immunotrex to develop the findings in the paper,” he says. Immunotrex is one of the startup companies at the Massachusetts Medical Device Development Center at Wannalancit.

“The CEO of the company, Syed Hasan, MD., is also my Ph.D. student, and we are working on developing a secreted tau biosensor that could be easy and inexpensive enough to use to screen the many millions of people who are at risk for developing Alzheimer’s disease,” he says.